The present invention relates to a vertical boring and turning mill, more specifically, to a machine of this type in which the workpieces are held or secured on the so called table arranged adjacent to an upright post which supports a cross beam above the table. Several supports are carried by the cross beam, which guides horizontal carriages for their horizontal adjustment or displacement. The horizontal carriages in turn carry vertically adjustable slides which in turn hold the tools.
Such machines are also known as vertical turret boring machines and several modifications are well known in the art. Such machines are used for the turning of very heavy workpieces having large diameters. The workpieces are secured to a horizontal turning table which rotates during the working of the machine much like a merry-go-round. Depending on the type of load for which any particular machine is designed, these machines are provided with a movable or a rigid, stationary cross beam which carries one or several so called supports for the working of a workpiece. Each support comprises normally a horizontal slide which is adjustable in parallel to the cross beam in the horizontal direction and a vertical slide which is adjustable in the vertical direction perpendicularly to the cross beam. The vertical slide normally carries the tools.
Heretofore it was customary to provide a separate drive and control mechanism for each of the two adjustments. In other words, each slide used to have its own drive and control mechanism for the feed advance as well as for the rapid advance. Such drive means are rather expensive, especially if they require so called "NC" controls. However, such costs cannot be avoided if it is required that several supports work simultaneously on the workpiece. However, in many instances such simultaneous use of several supports is not necessary. In practice, it is rather the rule that the individual supports are employed sequentially one after the other for performing the required working operations.